Hi, i am trying to reproduce this project on my Celestron 8 SE. But i found that Celestron 8 SE, there is no obvious way to measure the focuser tube traveling distance for one knob revolution.
Do you guys know how to work around this problem? is this parameter a must for the program to work?
Thanks.

It is not a must. My discussion on travel distance was to work out an estimate for limits to the maximum number of steps the driver will allow. The author was looking at 20,000 step limit, and I calculated the most I could possibly need, and was satisfied I came within it.

That's good to hear. I am glad that you are still monitoring the thread.
I need to look at the code more closely to figure out what exactly i need to provide for the focuser to work.

At the Ekos UI side, it looks i only need to set the ticks properties for the Max Travel

Settings
Max Travel: Maximum travel in ticks before the autofocus process aborts.
Step: Initial step size in ticks to cause a noticeable change in HFR value.
Tolerance: The tolerance percentage values decides when the autofocus process stops in the Iterative algorithm.

Hi all,

I have ordered te ADAFruit DC and stepper motor HAT for raspberry PI 3b+ to build my focusser. Any suggestions on the type of stepper motor I should buy with it?

Kind regards,
Gunther

It depends on the load you want to carry on a draw tube. In any case I would suggest 12V stepper motor with no more than 1A current. I have tested some 5V motors and they seem to weak.

No eBay APP ID and/or Cert ID defined in Kunena configurationHi Gunther, in addition to what Radek just wrote: from my experience it is critical to have a gearbox attached. Without, the weight of the camera may pull the camera out of focus. The gearbox is a little bit like a had break in your car. The one I am working with right now is this one:



This shows how it can be attached:

github.com/HelgeMK/FocuserParts/blob/mas...icture%20Focuser.jpg

To be honest, I do not know what the best gear ratio is.

Thanks for the input.

By the end of the week the Adafruit Motor HAT will be in my local store. I'll ask for a 12V stepper motor and try to get that to work. Then I will begin with step two: putting it on my telescope. I have a Starway Crayford Focusser with a 10:1 micro focussing. A canon 700D will be attached to it.



This will be my second electronic DIY project after putting the raspberry PI together. So I'm a newbie on this topic

Gunther

Yesterday I received my Adafruit Motor HAT earlier then expect. So I started working on my focusser. In the image you can see the Adafruit Motor HAT attached to the Raspberry Pi and to a hybdrid stepper motor. I connected the stepper motor as a bipolar motor.

After installing the python driver I made a script so I could test the stepper motor. It all works well
Next step was installing the astroberry-diy. I followed the steps written on GitHub. I can find the focusser in Ekos. There is no error message, but the focusser is probably not working cause he doesn't respond.
I used the command : cmake -DWITH_WIRINGPI=OFF -DCMAKE_INSTALL_PREFIX=/usr ..
The Adafruit Motor HAT is working through GPIO, should i use the option -DWITH_WIRINGPI=ON ? Or do I need to do something else?

kind regards,
Gunther

For Adafruit Motor HAT you should use other driver. You can find it here github.com/rkaczorek/astroberry-amh
Good luck!

Kaczorek, would it be possible to make the drive mode selectable? As it is, to change from single step to microstep requires editing the source and recompiling.
Thanks.

Hi Kaczorek,

I have downloaded the suggested driver bu I have trouble with the last step for building the driver. It is the make install command.

Can you make something out of this message?

[ 10%] Performing update step for 'libAdafruitStepperMotorHAT'
Current branch master is up to date.
No stash found.
No stash found.
No stash found.
CMake Error at /home/stellarmate/astroberry-amh/build/libs/AdafruitStepperMotorHAT_CPP/tmp/libAdafruitStepperMotorHAT-gitupdate.cmake:136 (message):


Failed to unstash changes in:
'/home/stellarmate/astroberry-amh/libs/AdafruitStepperMotorHAT_CPP/'.

You will have to resolve the conflicts manually

CMakeFiles/libAdafruitStepperMotorHAT.dir/build.make:94: recipe for target 'libs/AdafruitStepperMotorHAT_CPP/src/libAdafruitStepperMotorHAT-stamp/libAdafruitStepperMotorHAT-update' failed
make[2]: *** [libs/AdafruitStepperMotorHAT_CPP/src/libAdafruitStepperMotorHAT-stamp/libAdafruitStepperMotorHAT-update] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/libAdafruitStepperMotorHAT.dir/all' failed
make[1]: *** [CMakeFiles/libAdafruitStepperMotorHAT.dir/all] Error 2
Makefile:127: recipe for target 'all' failed
make: *** [all] Error 2

It looks I have probably an older version of wiringpi. Updating this first.

Remove build/libs/AdafruitStepperMotorHAT_CPP before make install
OR
after make (it goes successfully) manually copy indi_amh_focuser to /usr/bin and indi_amh_focuser.xml to /usr/share/indi